1. Field of the Invention
The present invention relates to an array substrate and a display device, and more particularly, to an array substrate and a display device which include a display region having a non-quadrangle shape such as circle, ellipse, polygon (except quadrangle) or the like instead of a general quadrangle shape (square, rectangle).
2. Description of the Related Art
In recent years, the display device has been used as an information transferring means adapted in various apparatus for people. As an existing typical thin display device, an active matrix liquid crystal display device using an array substrate formed with a thin film transistor (TFT) becomes a mainstream, which has an excellent characteristic in display quality level, small thickness, light weight and power consumption.
In recent years, as the thin display device becomes a mainstream, products are required of various functions and shapes. Accordingly, there has been a request for a thin display device which has various non-quadrangle shapes of a display region, such as, circle, ellipse, polygon (except quadrangle) or the like instead of a quadrangle shape like a square or a rectangle.
As a display device having the above-mentioned request, for example, there are a cell-phone display device and a car-mounted display device. For example, liquid crystal display devices having these non-quadrangle display regions are disclosed in JP-A-2006-276359 (FIGS. 1 and 2), JP-A-2006-276360 (FIGS. 1, 2, and 13), and JP-A-2006-276361 (FIGS. 1, 2, and 12).
However, in the liquid crystal display device disclosed in JP-A-2006-276359, even though there is a description of scanning lead-out lines and signal lead-out lines disposed in a frame region on the outside of the display region along the shape of the display region, there is no detailed description of a sub-capacitance Cs for holding a voltage applied to the liquid crystal which is generally provided in the liquid crystal display device or sub-capacitance lines for forming the sub-capacitance Cs, and there is no detailed description of a layout of a common lead-out line for commonly connecting the sub-capacitance lines in the frame region.
Further, in a liquid crystal display device disclosed in JP-A-2006-276360, even though the sub-capacitance is provided, it adopts the Cs-on-Gate type where the sub-capacitance Cs is formed by being overlapped with the scanning line. However, in the current liquid crystal display device, the Cs-on-Common type is a mainstream where the sub-capacitance line is separated with and disposed along the scanning line or the signal line. Moreover, there is no detailed description of a configuration adopting the Cs-on-Common type for the liquid crystal display device having the non-quadrangle display region.
Further, in the liquid crystal display device disclosed in JP-A-2006-276361, it also adopts the Cs-on-Gate type where the sub-capacitance Cs is formed by being overlapped with the scanning line. FIG. 12 shows the use of the Cs-on-Common type as a related art, and the liquid crystal display device having an elliptic display region is illustrated. However, it is described that a line Zn (sub-capacitance line) connected to a sub-capacitance electrode may give rise to disconnection of the line or short-circuiting between the lines. Further, it is illustrated, for example, that the line Zn is connected to the outermost line Z (common lead-out line) in a frame region lower left of the elliptic display region, and the line Zn intersects the both lead-out lines of a scanning line X1 (scanning lead-out line) and a signal line Y1 (signal lead-out line) located at the frame region. However, there is no detailed description that the line Zn is connected to the line Z by using what kind of layered structure.